document.write( "Question 432892: Here I go again.....now, with negatives in the problem...I'm stumped!!! I am trying to help my daughter find the root of a quadratic equation using standard form. y=x^2-17x+30. Thanks for your input!!! \n" ); document.write( "
Algebra.Com's Answer #300065 by Edwin McCravy(20055)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "It's rootS, not root!  A quadratic equation \r\n" );
document.write( "usually has 2 roots, occasionally just 1 and sometines none at all.\r\n" );
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document.write( " y = x² - 17x + 30\r\n" );
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document.write( "We factor the right side\r\n" );
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document.write( "Write this:\r\n" );
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document.write( " y = (x     )(x    )\r\n" );
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document.write( "Think of two whole numbers whose product is 30\r\n" );
document.write( "and whose sum (since the last sign is +) is 17\r\n" );
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document.write( "They are 15 and 2 because 15·2 = 30 and 15+2 = 17\r\n" );
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document.write( "So fill in 15 and 2 on the right of each parentheses:\r\n" );
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document.write( " y = (x   15)(x   2)\r\n" );
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document.write( "Since the sign of 17 is -, both signs are -, so we have\r\n" );
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document.write( " y = (x - 15)(x - 2)\r\n" );
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document.write( "Set each parenthetical expression equal to zero.\r\n" );
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document.write( "   x - 15 = 0   and   x - 2 = 0\r\n" );
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document.write( "        x = 15  and       x = 2\r\n" );
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document.write( "are the two roots of the equation  \r\n" );
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document.write( "x² - 17x + 30 = 0\r\n" );
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document.write( "which are the two x-intercepts of the graph of\r\n" );
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document.write( "y = x² - 17x + 30 = 0\r\n" );
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document.write( "Edwin
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